package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.hmdp.dto.Result;
import com.hmdp.dto.ScrollResult;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Blog;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.BlogMapper;
import com.hmdp.service.IBlogService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IFollowService;
import com.hmdp.service.IUserService;
import com.hmdp.utils.SystemConstants;
import com.hmdp.utils.UserHolder;
import jodd.util.StringUtil;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.ZSetOperations;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.*;
import java.util.stream.Collectors;

import static com.hmdp.utils.RedisConstants.*;


@Service
public class BlogServiceImpl extends ServiceImpl<BlogMapper, Blog> implements IBlogService {
    @Resource
    private IUserService userService;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private IFollowService followService;

    /**
     * 查看探店笔记
     *
     * @param id
     * @return
     */
    @Override
    public Result queryBlogById(Long id) {
        //1.查询blog
        Blog blog = this.getById(id);
        if (blog == null) {
            return Result.fail("笔记不存在");
        }
        //2.查询blog相关用户
        queryBlogByUser(blog);
        //3.判断笔记是否被当前用户点赞
        isBlogLiked(blog);
        return Result.ok(blog);

    }

    /**
     * 查询热门博客
     *
     * @param current
     * @return
     */
    @Override
    public Result queryHotBlog(Integer current) {
        // 根据用户查询
        Page<Blog> page = query()
                .orderByDesc("liked")
                .page(new Page<>(current, SystemConstants.MAX_PAGE_SIZE));
        // 获取当前页数据
        List<Blog> records = page.getRecords();
        // 查询用户
        records.forEach(this::queryBlogByUser);
        //判断笔记是否被当前用户点赞
        records.forEach(this::isBlogLiked);
        return Result.ok(records);
    }

    /**
     * 点赞-set类型
     * @param id
     * @return
     */
//    public Result likeBlog(Long id) {
//        //1.获取登录用户
//        Long userId = UserHolder.getUser().getId();
//        //2.判断当前登录用户是否已经点赞
//        String key = BLOG_LIKED_KEY + id;
//        Boolean isMember = stringRedisTemplate.opsForSet().isMember(key, userId.toString());
//        if(BooleanUtil.isFalse(isMember)){
//            //3.未点赞，可以点赞
//            //3.1 数据库点赞数+1
//            boolean isSuccess = update().setSql("liked = liked + 1").eq("id", id).update();
//            //3.2 保存用户到Redis的set集合
//            if(isSuccess){
//                stringRedisTemplate.opsForSet().add(key,userId.toString());
//            }
//        }else{
//            //4.如果已经点赞，取消点赞
//            //4.1 数据库点赞数-1
//            boolean isSuccess = update().setSql("liked = liked - 1").eq("id", id).update();
//            //4.2 把用户从Redis的set集合移除
//            if(isSuccess){
//                stringRedisTemplate.opsForSet().remove(key,userId.toString());
//            }
//        }
//        return Result.ok();
//    }

    /**
     * 点赞-- ZSet
     *
     * @param id
     * @return
     */
    public Result likeBlog(Long id) {
        //1.获取登录用户
        Long userId = UserHolder.getUser().getId();
        //2.判断当前登录用户是否已经点赞
        String key = BLOG_LIKED_KEY + id;
        //尝试获取当前用户的score属性值
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        //如果score为null，则表示集合中没有该用户
        if (score == null) {
            boolean isSuccess = update().setSql("liked = liked + 1").eq("id", id).update();
            //更新成功，则将点赞用户id加入SoredSet集合，score属性值就是当前时间戳（默认按照从小到大排序）
            if (isSuccess) {
                stringRedisTemplate.opsForZSet().add(key, userId.toString(), System.currentTimeMillis());
            }
        } else {
            //如果当前用户已点赞，则取消点赞
            boolean isSuccess = update().setSql("liked = liked - 1").eq("id", id).update();
            //4.2 把用户从Redis的Sortedset集合移除
            if (isSuccess) {
                stringRedisTemplate.opsForZSet().remove(key, userId.toString());
            }
        }
        return Result.ok();
    }

    /**
     * 点赞排行榜
     *
     * @param id
     * @return
     */
    @Override
    public Result queryBlogLikes(Long id) {
        String key = BLOG_LIKED_KEY + id;
        //1.查村SortedSet集合的前5个元素--即用户id（不包含元素的分数）
        Set<String> top5 = stringRedisTemplate.opsForZSet().range(key, 0, 4);
        //如果返回的set集合是空--即没人点赞，直接返回一个空的list集合
        if (top5 == null || top5.isEmpty()) {
            return Result.ok(Collections.emptyList());
        }
        //2.解析top5中的用户id
        List<Long> ids = top5.stream().map(Long::valueOf).collect(Collectors.toList());
        //把ids集合拼成一个以“，”分隔的字符串
        String idsStr = StrUtil.join(",", ids);
        //3.根据用户id查询用户 WHERE id IN ( 5 , 1 ) ORDER BY FIELD(id, 5, 1)
        List<UserDTO> userDTO = userService.query().in("id", ids)
                .last("order by field(id," + idsStr + ")")
                .list().stream()
                //将查询的用户隐私信息隐藏
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());
        return Result.ok(userDTO);
    }

    /**
     * 保存探店笔记--并使笔记发布就推送到粉丝
     *
     * @param blog
     * @return
     */
    @Override
    public Result saveBlog(Blog blog) {
        //1.获取登录用户
        UserDTO user = UserHolder.getUser();
        blog.setUserId(user.getId());
        //2.保存探店笔记
        boolean isSuccess = save(blog);
        if(!isSuccess){
            return Result.fail("笔记保存失败");
        }
        //3.查询笔记作者的所有粉丝
        List<Follow> follows = followService.query().eq("follow_user_id", user.getId()).list();
        //4.推送笔记id给所有粉丝
        for (Follow follow : follows) {
            //4.1 获取粉丝id
            Long userId = follow.getUserId();
            //4.2 推送
            String key = FEED_KEY + userId;
            stringRedisTemplate.opsForZSet().add(key,blog.getId().toString(),System.currentTimeMillis());
        }
        //5.返回id
        return Result.ok(blog.getId());
    }

    /**
     * 关注推送页面的笔记查询---滚动查询
     * @param max
     * @param offset
     * @return
     */
    @Override
    public Result queryBlogOfFollow(Long max, Integer offset) {
        //1.获取当前用户
        Long userId = UserHolder.getUser().getId();
        //2.查询收件箱 ZREVRANGEBYSCORE key Max Min LIMIT offset count
        String key = FEED_KEY + userId;
        Set<ZSetOperations.TypedTuple<String>> typedTuples = stringRedisTemplate.opsForZSet()
                .reverseRangeByScoreWithScores(key, 0, max, offset, 2);
        //非空判断
        if(typedTuples == null || typedTuples.isEmpty()){
            return Result.ok();
        }
        //3.解析数据 blogId,minTime(时间戳）,offset(偏移量）
        List<Long> ids = new ArrayList<>(typedTuples.size());
        long minTime = 0; //记录当前最小值
        int os = 1; //偏移量，用来计数
        for (ZSetOperations.TypedTuple<String> tuple : typedTuples) {
            //获取id
            ids.add(Long.valueOf(tuple.getValue()));
            //获取分数（时间戳）
            long time = tuple.getScore().longValue();
            if(time == minTime){
                //当前时间等于最小时间，偏移量+1
                os++;
            }else{
                //当前时间不等于最小时间，重置
                minTime = time;
                os = 1;
            }
        }
        //4.根据id查询blog（使用in查询的数据默认按照id升序排序，这里需要使用我们自己的排序方式）
        String idStr = StrUtil.join(",", ids);
        List<Blog> blogs = query().in("id", ids).last("order by field(id," + idStr + ")").list();
        for (Blog blog : blogs) {
            //查询blog有关的用户
            queryBlogByUser(blog);
            //查询blog是否被点赞
            isBlogLiked(blog);
        }
        //5.封装并返回
        ScrollResult scrollResult = new ScrollResult();
        scrollResult.setList(blogs);
        scrollResult.setOffset(os);
        scrollResult.setMinTime(minTime);
        return Result.ok(scrollResult);
    }

    /**
     * 查询博客相关用户信息
     * @param blog
     */
    private void queryBlogByUser(Blog blog){
            Long userId = blog.getUserId();
            User user = userService.getById(userId);
            blog.setName(user.getNickName());
            blog.setIcon(user.getIcon());
    }

    /**
     * 判断用户是否已经点赞了
     * @param blog
     */
    private void isBlogLiked(Blog blog){
        //1.获取登录用户
        UserDTO user = UserHolder.getUser();
        if(user == null){
            //用户未登录，无需查询是否点赞
            return;
        }
        //2.获取当前用户信息
        Long userId = user.getId();
        //3.判断当前用户是否点赞
        String key = BLOG_LIKED_KEY + blog.getId();
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        //4.如果已经点赞了，则将Blog类中的isLike属性设置为true
        blog.setIsLike(score !=null);
    }
}

